diff --git a/src/actions.cc b/src/actions.cc
index f08bdff..cc1efd4 100644
--- a/src/actions.cc
+++ b/src/actions.cc
@@ -1,56 +1,61 @@
-#include "ogg.h"
-
-// Here we're going to illustrate how to use the ogg module.
+#include "actions.h"
 
 using namespace opustags;
 
-enum StreamSelection {
-	ALL_STREAMS = -1,
-	FIRST_STREAM = -2,
-};
-
-void list_tags(ogg::Decoder *reader, long select)
+void opustags::list_tags(ogg::Decoder &dec, TagsHandler &handler)
 {
-	ogg::Stream *s;
-	while ((s = reader->read_page()) != NULL) {
-		if (s->state == ogg::TAGS_READY && (select == ALL_STREAMS || select == FIRST_STREAM || s->stream.serialno == select)) {
-			// print_tags(s->tags);
-			if (select != ALL_STREAMS)
-				break;
-		}
-	}
+    ogg::Stream *s;
+    while (!handler.done()) {
+        s = dec.read_page();
+        if (s == NULL)
+            break; // end of stream
+        switch (s->state) {
+            case ogg::HEADER_READY:
+                if (!handler.relevant(s->stream.serialno))
+                    s->downgrade();
+                break;
+            case ogg::TAGS_READY:
+                handler.list(s->stream.serialno, s->tags);
+                break;
+            default:
+                ;
+        }
+    }
 }
 
-void delete_tags(ogg::Decoder *reader, opustags::ogg::Encoder *writer, long select)
+void opustags::edit_tags(ogg::Decoder &in, ogg::Encoder &out, TagsHandler &handler)
 {
-	ogg::Stream *s;
-	while ((s = reader->read_page()) != NULL) {
-		switch (s->state) {
-		case ogg::HEADER_READY:
-			// TODO what if select == FIRST_STREAM?
-			if (select != ALL_STREAMS && s->stream.serialno != select)
-				// act like nothing happened and copy this "unknown" stream identically
-				s->type = ogg::UNKNOWN_STREAM;
-			// fall through
-		case ogg::RAW_READY:
-			writer->write_raw_page(reader->current_page);
-			break;
-		case ogg::TAGS_READY:
-			// only streams selected at HEADER_READY reach this point
-			writer->write_tags(s->stream.serialno, ogg::Tags());
-			break;
-		case ogg::DATA_READY:
-			writer->write_page(reader->current_page);
-			break;
-		default:
-			;
-		}
-	}
+    ogg::Stream *s;
+    while (true) {
+        s = in.read_page();
+        if (s == NULL)
+            break; // end of stream
+        switch (s->state) {
+
+            case ogg::HEADER_READY:
+                if (!handler.relevant(s->stream.serialno)) {
+                    s->downgrade();
+                    out.write_raw_page(in.current_page);
+                } else {
+                    out.write_page(in.current_page);
+                }
+                break;
+
+            case ogg::TAGS_READY:
+                handler.edit(s->stream.serialno, s->tags);
+                out.write_tags(s->stream.serialno, s->tags);
+                break;
+
+            case ogg::DATA_READY:
+                out.write_page(in.current_page);
+                break;
+
+            case ogg::RAW_READY:
+                out.write_raw_page(in.current_page);
+                break;
+
+            default:
+                ;
+        }
+    }
 }
-
-// To write edit_tags, we're gonna need something like the options structure in
-// order to know what to do exactly.
-
-// The command-line interface has yet to be done, but it'd be nice it let the
-// user edit several streams at once, like :
-// $ opustags --stream 1 --set TITLE=Foo --stream 2 --set TITLE=Bar
diff --git a/src/actions.h b/src/actions.h
index 6cb021f..8836df9 100644
--- a/src/actions.h
+++ b/src/actions.h
@@ -1,12 +1,10 @@
 #pragma once
 
+#include "tags.h"
 #include "ogg.h"
 
 namespace opustags {
 
-    // To be defined properly somewhere.
-    class Tags;
-
     // TagsHandler define various operations related to tags and stream in
     // order to control the main loop.
     // In its implementation, it is expected to receive an option structure.
diff --git a/src/ogg.h b/src/ogg.h
index 5631e47..740dff0 100644
--- a/src/ogg.h
+++ b/src/ogg.h
@@ -5,11 +5,11 @@
 #include <map>
 #include <ogg/ogg.h>
 
+#include "tags.h"
+
 namespace opustags {
 namespace ogg
 {
-    typedef std::map<std::string, std::string> Tags;
-
     enum StreamState {
         BEGIN_OF_STREAM,
         HEADER_READY,
diff --git a/src/tags.h b/src/tags.h
new file mode 100644
index 0000000..56be00b
--- /dev/null
+++ b/src/tags.h
@@ -0,0 +1,8 @@
+#pragma once
+
+namespace opustags {
+
+    class Tags {
+    };
+
+}